Within many different technical fields, like for example merchant ships, offshore platforms and buildings with content of high importance there are several safety aspects that must be considered to avoid severe damages to the content within the structure as well as peoples working in or close to the area in case of accidents like for example fire or leaking water from the outside or within the platform, ship or building.
In case of explosion, fire or leaking water the fire and/or leaking water are often spread along wires, cables or pipes and in order to stop, or at least delay, the fire or water from spreading each cable, wire or pipe is sealed where they are lead through partition walls within the platform, ship or building.
One frequently used sealing system that is frequently used to provide a reliable sealing of cables, wires or pipes extending through partition walls involves a metal frame permanently installed in the wall to provide a passage of a predetermined size for the cables, wires or pipes in the desired area of the wall. The cables, wires or pipes are during installation lead through the frame. The space within the frame is during installation of the sealing filled with insert blocks packed in layers within the frame to completely fill the space within the frame. Each insert block consist of two block halves each provided with a semi-circular groove in one side of the block half such that a circular passage is generated through the insert block when the two block halves are put together. Each cable, wire or pipe extending through the frame is fitted in an insert block and packed within the frame. The outside dimension of the insert blocks is selected so that a predetermined number of insert blocks have a size corresponding to the space within the frame. After the blocks are packed side by side in layers in the intended position a pressure applying device is arranged in the top part of the frame. The pressure applying device, upon activation, applies a pressure on the blocks to press the blocks together and provide the desired sealing around the cables, wires or pipes within the frame.
However, in order to achieve the desired sealing the diameter of the passage in the insert block must correspond to the diameter of the cable, wire or pipe. The desired tight fitting is either achieved by using a number of insert blocks with different diameters of the passage or by an insert block with a larger passage and a number of peelable layers arranged in the groove such that a selected number of layers could be removed and the diameter of the passage adapted to each of the different cables, wires or pipes extending through the frame.
Recently, installation of the above described sealing system in combination with a new type of cable was initiated. The new cable is intended for optical fibres and comprises a number of small pipes extending within the cable. In order not to damage the optical fibres during the installation work of the cable, the fibres are preferably introduced in their respective pipe at a later stage when the installation work of the cable is completed by blowing the fibres and air through the pipes. Unfortunately, the pressure applied by the sealing system to seal the space around the insert blocks within the frame resulted in deformations of the cable and the small pipes within the cable which made it difficult to introduce the optical fibres.
There is consequently a need for an improved insert block, and sealing system, that ensures the desired sealing around the cable, or cables, without affecting the possibilities to introduce the optical fibres in the respective pipe.